Flashcards in Repro - Embryology (Aortic/Branchial derivatives & Cleft lip/palate) Deck (50)
Into what do aortic arch derivatives develop?
Develop into the arterial system
What is derived from the 1st aortic arch? Of what major vessel is this a branch?
Part of maxillary artery (branch of external carotid); Think: "1st arch is MAXimal"
What is derived from the 2nd aortic arch?
Stapedial artery and Hyoid artery; Think: "Second = Stapedial"
What is derived from the 3rd aortic arch?
Common Carotid artery and proximal part of internal Carotid artery; Think: "C is 3rd letter of alphabet"
What is derived from the 4th aortic arch?
On left, aortic arch; on right, proximal part of right subclavian artery; Think: "4th arch (4 limbs) = systemic"
What is derived from the 6th aortic arch?
Proximal part of pulmonary arteries and (on left only) ductus arteriosus; Think: "6th arch = pulmonary and the pulmonary-to-systemic shunt (ductus arteriosus)"
How do right and left recurrent laryngeal nerves relate to the aortic arch?
See p. 558 in First Aid 2014 for visual
What is another name for the branchial apparatus? What are its 3 components?
Also called pharyngeal apparatus; Composed of branchial clefts, arches, and pouches
From what germ layer are branchial clefts derived?
Derived from ectoderm
What is another name for branchial clefts?
Also called branchial grooves
From what 2 embyrological origins are branchial arches derived? What are 2 examples of each source?
Derived from mesoderm (muscles, arteries) and neural crest (bones, cartilage)
From what germ layer are branchial pouches derived?
Derived from endoderm
List the components of the branchial apparatus from outside to inside. What germ layer gives rise to each?
Clefts = ectoderm, Arches = mesoderm, Pouches = endoderm; Think: "CAP covers outside to inside"
Draw a visual of the branchial apparatus including and labeling the following: (1) Arches (2) Cleft (3) Epicardial ridge (4) Pharyngeal arches - 1st through 4th (5) Pouch (6) Primitive esophagus (7) Primitive pharynx.
See p. 558 in First Aid 2014 for visual near bottom right of page
Into what does the 1st branchial cleft develop?
1st cleft develops into external auditory meatus
What do the 2nd through 4th clefts form? What is the fate of this (these) structure(s), and what causes this?
2nd through 4th clefts form temporary cervical sinuses, which are obliterated by proliferation of 2nd arch mesenchyme
What abnormality does a persistent cervical sinus cause, and where?
Persistent cervical sinus => branchial cleft cyst within lateral neck
To what kind of cartilage does the 1st branchial arch give rise? What are 3 structures that result?
Meckel cartilage: (1) Mandible (2) Malleus (3) spheno-Mandibular ligament; Think: "M's (also like most of its muscle derivatives)"
To what 8 muscle derivatives does the 1st branchial arch give rise?
Muscles of Mastication [(1) temporalis (2) Masseter (3) lateral and (4) Medial pterygoid], (5) Mylohyoid, (6) Anterior belly of digastric, (7) Tensor tympani, (8) Tensor veli palatini; Think: "M's, also like most of cartilage derivatives)
To what 2 nerve derivatives does the 1st branchial arch give rise?
CN V2 and V3; Think: "chew (like Muscles of Mastication)"
What abnormality is associated with 1st branchial arch? What causes this? What 2 symptoms/signs result?
Treacher Collins syndrome: 1st-arch neural crest fails to migrate => (1)mandibular hypoplasia, (2) facial abnormalities
To what kind of cartilage does the 2nd branchial arch give rise? What are 4 structures that result?
Reichert cartilage: (1) Stapes (2) Styloid process (3) lesser horn of hyoid (4) Stylohyoid ligament; Think: "S's (also most of muscle derivatives)"
To what 5 muscles does the 2nd branchial arch give rise?
(1) Muscles of facial expression, (2) Stapedius, (3) Stylohyoid, (4) platySma, (5) belly of diastric; Think: "S's (also most of cartilage derivatives)"
To what nerve does the 2nd branchial arch give rise?
CN VII (facial expression); Think: "smile (like S's of most cartilage and muscle derivatives)
What abnormality is associated with the 2nd branchial arch? What causes this disorder? What symptom/sign results, and where?
Congenital pharyngo-cutaneous fistula: persistence of cleft and pouch => fistula between tonsilar area and lateral neck
To what cartilage does the 3rd branchial arch give rise?
Cartilage: greater horn of hyoid
To what muscle does the 3rd branchial arch give rise?
Stylopharyngeus; Think: "styloPHARYNGEUS innervated by glossoPHARYNGEAL nerve"
To what nerve does the 3rd branchial arch give rise?
CN IX; Think: "STYLOpharygeus SWALLOW STYLishly"
To what 5 cartilages do the 4th through 6th arches?
Cartilages: (1) Thyroid, (2) Cricoid, (3) Arytenoids, (4) Corniculate, (5) Cuneiform